Other Noninterest Income and Other Noninterest Expense - Summary of Other Noninterest Income (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Other Noninterest Income [Line Items]
Fund management fees		$ 5,169	$ 4,620
Service-based fee income		1,895	2,092
Unrealized Gain (Loss) on Derivatives		(3,887)	(3,159)
Other (3)		4,029	2,676
Total other noninterest income	[1]	12,421	7,670
Client Instruments
Other Noninterest Income [Line Items]
Gains on revaluation of internal foreign currency instruments, net (2)		2,754	3,653
Internal Instruments
Other Noninterest Income [Line Items]
Gains on revaluation of internal foreign currency instruments, net (2)		4,108	2,491
Derivatives not designated as hedging instruments | Foreign Exchange Contract
Other Noninterest Income [Line Items]
Unrealized Gain (Loss) on Derivatives		863	283
Derivatives not designated as hedging instruments | Other derivative instruments
Other Noninterest Income [Line Items]
Unrealized Gain (Loss) on Derivatives		465	(2,001)
Other noninterest income | Derivatives not designated as hedging instruments | Foreign Exchange Contract
Other Noninterest Income [Line Items]
Unrealized Gain (Loss) on Derivatives		(3,245)	(2,208)
Other noninterest income | Derivatives not designated as hedging instruments | Other derivative instruments
Other Noninterest Income [Line Items]
Unrealized Gain (Loss) on Derivatives		$ (2,289)	$ (5,654)

[1] Our consolidated statements of income were modified from prior period's presentation to conform to the current period's presentation, which reflects a new line item to separately disclose net gains on equity warrant assets. In prior periods, net gains on equity warrant assets were reported as a component of gains on derivative instruments, net. We removed the line item gains on derivative instruments, net and reclassified all other gains on derivative instruments, net to other noninterest income.